Chad Bowers didn’t learn about his favorite new workout at the gym or by reading an article about it. He watched videos on YouTube, where people have posted thousands of clips of themselves jumping over benches and railings, leaping down flights of stairs, climbing up walls and fences, and swinging from playground equipment and tree branches.

They’re practicing parkour, an extreme sport rooted in French military training that has been spreading to cities across America. Parkour fans are typically people like Bowers who discover it on the Internet and then start up local parkour clubs that get together for “jams.”

Bowers, 20, a junior at Drury University in Springfield, Mo., started practicing parkour almost a year ago. He met with more experienced practitioners – known as “traceurs” (males) or “traceuses” (females) — in Kansas City and St. Louis, and he and a friend created a group called Springfield Parkour.

The group is organized on Facebook and gathers on Saturdays at a local park where activities include warming up, performing calisthenics and practicing moves such as landing and rolling. Then they go “run around downtown Springfield,” says Bowers, jumping and climbing on benches, fountains and parking garages.

Essentially, the world is one big playground for them.

Running, jumping and rolling on cement or vaulting over walls — usually without protective gear — might not seem all that appealing or smart to the average person. But parkour and a related activity called freerunning have been glamorized in videos, TV commercials and movies such as “Casino Royale,” attracting young people — mostly guys, though more women and girls are getting involved — who are seeking out new adventure and alternative ways to get in shape.

“I like that it is a great workout, a total body workout,” says Bowers. “It’s a great way to challenge yourself, to test what your mind can do, and it’s also a lot of fun.”

Sometime later this year, MTV is planning to air a special titled “Ultimate Parkour Challenge,” which will feature eight top parkour athletes competing and performing stunts such as jumping between buildings. Victor Bevine, one of the show’s co-executive producers and a co-founder of the World Freerunning and Parkour Federation, of which the eight athletes belong, says the show is “very much not ‘Jackass.’” The athletes have prepared extensively for their stunts, he says.

Parkour is often defined as getting from “point A to point B as quickly and efficiently as possible using only the human body,” says Mark Toorock, a parkour trainer who owns the gym Primal Fitness in Washington, D.C., and runs americanparkour.com.

But that definition isn’t entirely accurate, Toorock says. For example, the quickest and most efficient way to travel three city blocks would be to run straight, not climb and jump over nearly every object along the way. “We do it for training purposes because walking up the stairs doesn’t challenge us,” he says.

Freerunning is an offshoot of parkour that refers to creative moves such as flips and spins and other gymnastic-style stunts.

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Risks for the overly daringNobody knows how many people practice parkour, but Bevine estimates the number is in the “tens of thousands” worldwide. “It is the fastest growing extreme sport in the world,” he claims.

Toorock agrees that the sport, which he says was introduced to America around 2004, is “definitely growing,” particularly in urban areas such as Miami, Chicago, Denver, Washington, D.C., and San Francisco.

While parkour fans enjoy the thrills and freedom of the sport, it can carry risks, particularly for the untrained and the overly daring.

Some of the top parkour athletes, such as parkour originator and French actor David Belle and the competitors in the MTV show, might jump from one rooftop to another, but that’s not what average parkour practitioners do, Toorock says.

“Our message is very clear — you have to practice safely,” he says. At his gym, people practice their moves indoors with trainers, learning how to land and roll safely before heading outdoors. Participants are advised to take things slowly, hone their techniques and get in strong physical shape.

While there are no statistics on injuries from parkour, Jeffrey Ross, a spokesperson for the American College of Sports Medicine and an associate clinical professor at Baylor College of Medicine in Houston, suspects there could be a significant number.

Never a dull moment
With all the jumps and falls, participants risk stress fractures, ankle and knee sprains, and ligament injuries, among other potential problems, says Ross, a foot and ankle specialist. And the sport could be quite dangerous if participants attempted over-the-top stunts such as jumping from one building to another, he says.

It would be a huge mistake for beginners fascinated by the performances of elite parkour athletes on a TV show or Web video to take the sport too far too fast, cautions Jessica Matthews, a personal trainer and spokesperson for the American Council on Exercise in San Diego.

“I fear that individuals won’t realize the amount of work and groundwork that these [top parkour athletes] have gone through to get to that point,” she says.

Above all, she advises, “Don’t just view a video and go out and try to recreate that.”

And while parkour practitioners relish the unfettered freedom of the sport, Matthews strongly recommends protective gear such as a helmet and elbow and knee pads, at the very least for beginners.

“The thrill is being out there and being free and being creative,” she says. “But the No. 1 concern for us is that it’s done safely.”

On the plus side, Matthews says, parkour may encourage physical fitness because it’s “outside of the box.” In particular, it may appeal to people who would otherwise not stay active because they don’t like exercising in “the confines of a gym.”

That was a big draw for Phil Howe, 24, who trains at Primal Fitness in Washington, D.C., and goes to local parkour jams.

“I wanted to do something that wasn’t so rules-based, or going to a gym and staying in a gym,” he says.

And with parkour, there’s never a dull moment, says Howe. “My biggest goal is to keep things interesting and definitely there’s no lack of that.”